Devil May Cry 5 walkthrough/SM09

Location
On Mission 12: Yamato, in the underground area where Dante states "This takes me back", you will see the large Secret Mission pattern when going up, after reaching the top, turn the camera around and get to the location behind you. You may need to use the Trickster Style to get there.

Walkthrough
The goal of this Secret Mission is to stay in the air for at least 15 seconds, it's recommended to buy the Enemy Step ability from the Divinity Statue or Nico and have Ebony & Ivory equipped, then simply keep jumping off of the enemies and using E&I to stay in the air for longer. Using melee attacks in the air such as the Cavaliere's or while using the Swordmaster Style will also allow you to stay in the air for longer.

If the enemy moves away from Dante and you know you can't catch up to it, use the Trickster Style to teleport to it.